Cal. 928 appeared around 1985, reviving one of Jaeger-LeCoultre's signature complications, the "Réserve de Marche, or power reserve indicator. The company was the first to bring this complication to market in 1948 with the Cal. 481 Powerwind and has continued to market watches with this complication to today.
Cal. 928 an automatic movement based on the widely-produced Cal. 889/1. It runs at 28,800 A/h and has 43 jewels. It features central hour and minute hands and small seconds at 6:00. A subdial at about 2:30 shows the date by pointer.
But it is the retrograde power reserve pointer centered at 10:30 that gives the movement its claim to fame. It swings counter-clockwise from about 6:30 to about 4:00 and watches feature a scale marked "0 - 10 - 20 - 30 - 40" and the "Réserve de Marche" title.
Jaeger-LeCoultre currently used this calibre in watch models named for this complication, the Jaeger-LeCoultre Gentilhomme Réserve de Marche and Jaeger-LeCoultre Master Réserve de Marche. Cal. 928/2 is substantially similar. Cal. 928 was produced from about 1985 through about 2012, when the Jaeger-LeCoultre Master Ultra Thin Réserve de Marche with Cal. 938 was released.
Calibre 928 was also used by Vacheron Constantin as their Cal. 1127.